The present invention relates to a plasma liquid crystal display, and to a liquid crystal display using a plasma addressing method, including a plasma discharge electrode wherein anodes for applying data signals and cathodes for applying line scanning signals are arranged in an X-Y matrix, and a method for driving and gray-scale displays.
Along with the need for display media which can effectively display a great deal of information, and the development of the next generation of high-definition televisions (HDTV), flat-panel displays are currently being studied to improve the picture quality of HDTV as well as to realize a full-sized screen. One kind of such flat-panel display is a liquid crystal display using a plasma addressing method, which is constructed by uniting a plasma discharge device and a liquid crystal display of an electric field optical device. In the initial stages of construction, a liquid crystal display using a plasma addressing method is built such that stripe-like data electrodes are formed on the inner surface of a transparent face plate of a liquid crystal portion, and scanning lines are formed in grooves of a plasma addressing portion so as to intersect the stripe-like data electrodes at right angles.
Under this state, a rear plate is tightly fixed to an intermediary plate, so that the groove forms a sealed discharge space into which discharge gas is injected. However, in practical mass production, such a liquid crystal display using a plasma addressing method is difficult to make, due to the fastidious process of manufacturing the groove of the plasma addressing portion.
Therefore, ongoing research into the easy manufacture of a liquid crystal display using a plasma addressing method has continued. As a result, a novel liquid crystal display using a plasma addressing method has developed wherein its discharge electrodes are arranged as an X-Y matrix, and its structure is as follows.
A transparent face plate of a liquid crystal portion and a rear plate are disposed in such a manner so as to be spaced apart from each other by a predetermined distance, column electrodes are formed on the inner surface of the transparent face plate, and liquid crystal is injected between the face plate and an intermediary plate to form a liquid crystal layer. In addition, cathodes for supplying scanning signals are formed on the inner surface of the rear plate while crossing the column electrodes at right angles, and anodes are formed parallel to the column electrodes. FIG. 1 is a diagram for illustrating a method for driving a liquid crystal display using a plasma addressing method with the structure described above.
When a discharge potential on a selected scanning line is created by successively supplying scanning signals to cathodes 23 (that is, so as to conduct), data electrodes 14 positioned over cathodes 23 are supplied with data signals, thereby forming an electric field at the intersecting portions of these electrodes. Thus, the liquid crystal layer at the selected portion is rearranged. Accordingly, light from a background light source (not shown) placed on the rear plate of a discharging portion is formed due to the discharge potential, and then passes through the discharging portion. At this time, all anodes 22 are at ground potential.
In the above-described conventional liquid crystal display using a plasma addressing method, the jointly operating addressing portion and liquid crystal portion are each controlled by its own driving IC, thus decreasing the speed and accuracy of such a liquid crystal display. Moreover, since a driving voltage applied to the liquid crystal portion is low, the intermediary plate must be extremely thin in order to allow for the rearrangement of the liquid crystal in the liquid crystal portion, which utilizes the discharge potential of plasma discharge cells. However, an extremely thin glass plate such as the type currently being used as transparent intermediary plates of the liquid crystal portion is difficult to produce.
Further, in the liquid crystal display using a plasma addressing method having the above-described structure, in order to display gray scale, a data signal is supplied to a column electrode of the liquid crystal portion and a scanning signal is supplied to a cathode of the plasma addressing portion. Hence, a pixel is turned on/off with just two signals, so that a more effective display of the gray scale is difficult.